(1) Field of the Invention
This invention is directed toward underwater power generation, and more particularly, to a flipper or fin which incorporates a piezoelectric element into its structure for generating electric power which can be used to electrically power auxiliary devices. This invention provides a means for generating electrical energy while scuba diving for a variety of applications, particularly, for powering electrical devices underwater.
(2) Description of the Prior Art
Scuba divers generally utilize flippers or fins as one means of underwater propulsion or thrust. In use the flippers are flexed back and forth in the water to enable a diver to move or maintain a particular depth. Flippers are generally formed from a flexible neutrally buoyant material and the size and shape of the flipper depends upon the diving conditions.
Frequently, it is necessary for a diver to use underwater equipment when diving. Much of this equipment requires electrical power and such equipment can be heavy. Because divers rely upon their physical resources while diving underwater, the weight of the equipment places an additional load on the diver. This equipment also generally requires underwater battery packs (electrochemical or storage cells) which can be equally as bulky and heavy as the equipment, adding further to the diver's load. A diver's physical stamina decreases as the load increases. Accordingly, any decrease in the load is beneficial to the diver.
An example of an electrical device for use in underwater diving would be lighting for use in night dives. Vision is poor in night dives, making it necessary to carry lighting so as to give the diver a direction and also to illuminate the diver for safety purposes. A solo diver with no buddy line is not clearly visible during night dives without lighting. Thus, it is necessary for the diver to carry lighting and a source to power the lighting. It would be beneficial in such situations if the diver was able to generate power for the lighting in the water as opposed to carrying a power source with him. Such a system is not shown in the prior art, however, some patents do exist which illustrate devices that generate power via the motion of objects.
U.S. Pat. No. 4,387,318 to Kolm et al. discloses a piezoelectric fluid-electric generator. The generator includes a piezoelectric bending element and means for mounting one end of the bending element in a fluid stream. A blade is provided which is mounted to the end of the bending element and which is adapted to be placed into the fluid stream. Electrode means, connected to the piezoelectric bending element, conduct current from the generator to a device. Upon placement of the blade in a fluid stream, the blade is caused to oscillate, which causes the bending element to oscillate, which generates electricity.
U.S. Pat. No. 4,404,490 to Taylor et al. discloses a device which generates power from waves near the surface of bodies of water. The device includes a piezoelectric structure comprising piezoelectric material members preferably in the form of sheets. Each sheet has an electrode on opposite surfaces thereof. Each pair of electrodes with the piezoelectric material therebetween defines a power generating element, each of which is preferably dimensioned, relative to the wave lengths of selected waves on the body of water in which a generator is used, for increasing the efficiency of power conversion. Further, a support means is provided for maintaining the structure in a preselected position within and below the surface of the water. The generating elements are preferably flexible and are supported in such a manner so as to allow flexure thereof in response to movement of the surrounding water.
U.S. Pat. No. 4,005,319 to Nilsson et al. discloses a piezoelectric generator operated by fluid flow. The generator for use with projectiles and the like comprises a piezoelectric element housed in a cavity through which air is forced during missile movement. A reed-like tongue in the cavity has one end captive while its other end is positioned near a ram air inlet. The ram air inlet terminates in a nozzle outlet which is aligned with the tongue and is so configured to enable ram air to impart vigorous vibration to the tongue. The piezoelectric element has a vibration transmitting connection with the tongue near the captive end of the latter for conducting electrical power to load circuitry in another part of the projectile.
U.S. Pat. No. 3,952,352 to Wan et al. discloses an electronic stroke effectiveness sensor for competitive swimmers. The sensor is a body worn apparatus that senses and measures the hydrodynamic thrust generated by a swimmer's hands as he strokes his hands through the water. The apparatus consists of pressure sensitive transducers that convert the thrust into electric signals that are fed back to the swimmer in terms of an audiotone. The frequency of the tone varies as a function of the thrust. Alternatively, the signals can be transmitted to a recording instrument calibrated to quantitatively meter and record the thrust generated by the swimmer's arm strokes.
While the above devices use a piezoelectric element for generating electrical power, none of the devices discussed are directed to a flipper or fin, for use underwater, for generating electric power in order to power underwater equipment. There exists, therefore, a need in this art for a piezoelectric power generating fin or flipper system for generating electricity underwater in order to ease the load now currently placed on divers when having to carry electrically powered devices and their power sources.